The invention relates to a device for continuous drying of a pulp sheet, particularly a tissue web, with a drying drum and an air circulating system.
In conventional tissue plants, the drying process begins at an inlet dryness of some 40 to 45% in the tissue web. In order to achieve higher paper volume, mechanical pre-dewatering on presses is omitted and the inlet dryness to this equipment nowadays is approximately 20 to 25%. These plants operate with through drying. If there is no paper in the plant, e.g. if there is a sheet break, there is a problem because the drying drum is exposed to high temperatures in the vicinity of the paper web for short periods and the difference in temperature between drum and end cover can cause increased stress and thus, damage to the drum. The aim of the invention is to eliminate this disadvantage.